Even more impressive, the dinosaur's tooth pressure - a new metric devised by the researchers - was even greater: an astounding 30 tonnes per square centimetre (431,000 pounds per square inch) of dental surface.

But even that may not have been enough to get the job done, the study found.

Saltwater crocodiles, the world's largest living reptiles, exert nearly as much pressure despite their much smaller size. They use that power, however, to capture not chew their prey, swallowing them whole instead.

The difference is that T. Rex - even if it lacked occluding teeth - still have the necessary equipment to make short work of bones.

"It had extraordinarily large, conical and strongly rooted teeth that were replaced after being worn every couple of years," Gignac explained.

The findings, reported in the journal Scientific Reports, show that "sophisticated feeding systems more commonly associated with modern mammals also appeared during the Age of Dinosaurs," he added.

Interestingly, the limit to T. Rex's bite force was probably not muscular, but the capacity of its teeth to withstand such intense stress.

Crocodiles and T. Rex "are probably operating at tooth pressures that are nearing the extreme structural limits of what reptilian tooth enamel can handle," Gignac said.

T. Rex's grip, in other words, may be just what is needed to fracture bones. Any more might have caused irreparable damage to the king's pearly whites.